avoid zero-length insert ops (#279)

fixes #276

Author: znck

.changeset/few-candles-care.md

@@ -0,0 +1,5 @@
+---
+'grammarly-richtext-encoder': patch
+---
+
+Fix markdown encoding when heading starts with a link

packages/grammarly-richtext-encoder/src/Language.ts

@@ -35,6 +35,7 @@ export function createTransformer(options: {
     }
 
     function insert(text: string, node?: Parser.SyntaxNode, skip: number = 0): void {
+      if (text === '') return
       richtext.ops.push({
         insert: text,
         attributes: text === '\n' ? pickBlockAttributes(attributes) : pickInlineAttributes(attributes),

packages/grammarly-richtext-encoder/src/LanguageMarkdown.ts

@@ -132,9 +132,13 @@ export const markdown = createTransformer({
   },
   processNode(node, insert) {
     if (node.type === 'text') {
-      if (node.parent?.parent?.type === 'atx_heading') {
+      if (node.parent?.parent?.type === 'atx_heading' && node.parent.firstChild?.equals(node)) {
         insert(node.text.slice(1), node, 1)
-      } else if (node.parent?.type === 'paragraph' && node.text.startsWith(': ')) {
+      } else if (
+        node.parent?.type === 'paragraph' &&
+        node.text.startsWith(': ') &&
+        node.parent.firstChild?.equals(node)
+      ) {
         insert(node.text.slice(2), node, 2) // #255 - Definition Lists
       } else insert(node.text, node)
     } else if (node.type === 'line_break' || node.type === 'hard_line_break') {

packages/grammarly-richtext-encoder/test/__snapshots__/markdown.test.ts.snap

@@ -52,12 +52,15 @@ exports[`markdown encode 1`] = `
   \\n
   First Term
    
-  This is the definition of the first term.
+  : This is the definition of the first term.
   \\n
   Second Term
    
-  This is one definition of the second term.
+  : This is one definition of the second term.
    
-  This is another definition of the second term.
+  : This is another definition of the second term.
   \\n
+  1 {"link":""}
+   header
+  \\n {"header":1}
 `;

packages/grammarly-richtext-encoder/test/markdown.md

@@ -38,3 +38,5 @@ First Term
 Second Term
 : This is one definition of the second term.
 : This is another definition of the second term.
+
+# [1] header